Inclinometers, and in particular inclinometers such as carpenter's levels which are used on construction sites need to be designed so that they can stand up to hard use. In the past, such carpenter's levels have been made from, for example, aluminum extruded I-beams, with a bubble sensor appropriately mounted onto the I-beam. Such I-beams cannot effectively resist torsional and bending loads which occur about the longitudinal axis of the level. Thus, the measuring device, such as the bubble sensor, is exposed to such torsional and bending loads. These torsional and bending loads can cause misalignment of the measuring device with respect to the rest of the I-beam rail and also can cause damage to the measuring device itself.
A more rigid level can be fashioned with a rail having either a solid rectangular cross-section or a hollow rectangular cross-section made by, for example, an extrusion process. These rails are known as box rails. They more effectively protect the sensing mechanism and also resist torsional and bending forces which can be placed on the sensing mechanism. Such box levels however are awkward and inconvenient to handle and hold in position. Thus, there exists a task of designing a ruggedized rail appropriate for a construction site or other such environment.
One solution to this task is disclosed in U.S. Pat. No. 4,912,662 entitled "Inclinometer" and issued on Mar. 27, 1990 and assigned to Wedge Innovations, Inc., the present assignee. The design of this inclinometer has a substantially wedge-shaped cross-section which is convenient for the user to hold. Additionally, the inclinometer disclosed in this patent is comprised of an I-beam cross-section with inserts to provide full torsional rigidity about the longitudinal axis of the inclinometer.